The large size of the Gato class generally allowed them to carry sufficient food and supplies for a 75 day patrol from Hawaii to Japan and back. Fuel, which was usually being burned all the time was the major deciding factor in determining when to break off a patrol. The Gato class boats all had air conditioning, refrigerated storage for food, and fresh water distilling units. Air conditioning operating as a dehumidifier was crucial in helping to keep food and stores from spoiling in the tropics. Plus, there are some accounts of a little trading going on with some of the Filipino and Indonesian sampans. Fresh tropical fruit for onboard trinkets.
